Temperature responsive valve



Jan. 19, 1965 H. F. MALONE ETAL TEMPERATURE RESPONSIVE VALVE Filed July 5. 1962 3,166,247 TEMPERAT RESPONSIVE VALVE Herner F. Malone and Lloyd E. Quint, Jackson, Mich.,

assignors, by mesne assignments, to Mechanical Prodacts, lne., Erickson, Mich., a corporation of Delaware Filed .lilly 3, 1962, Ser. No. 207,263 1 Claim. (Cl. 236--48) This invention relates generally to valves and more particularly to an improved temperature responsive valve.

Increasing awareness of the air pollution problem and the effect of internal combustion engine exhaust or air pollution has spurred the development of catalytic mufllers that oxidize many of the hydrocarbons contained in such exhaust gases. Such catalytic type mutllers eilect oxidization of the excess hydrocarbons in the exhaust gases of an internal combustion engine by a relatively high temperature process.

Upon the occurrence of certain conditions, yfor example, misring of the engine, at which time raw gasoline is discharged into the catalytic bed, the temperature ofthe bed may rise to dangerously high levels. When such a high temperature condition obtains, it is desirable to bypass the exhaust gases around the catalytic bed in order to allow the catalytic bed to cool off.

One Way to bypass the catalytic bed of such muillers is by using a vacuum operated ow control valve which directs the flow of exhaust gases either through the catalytic bed of the muiiler, r through a bypass. The vacuum operated flow control valve is, in turn, controlled by a temperature responsive valve that senses conditions within the catalytic bed of the muffler..

A temperature responsive valve suitable for controlling the flow control valve of a catalytic muier must be of relatively rugged construction so as to be impervious to the environmental conditions within the catalytic bed in which it operates, as Well as 'be responsive to `the temperature extremes to Iwhich it is subjected. It must be positive in operation, yet maintain its calibration through all temperature ranges.

A temperature responsive valve in accordance with the instant invention is designed to eiect positive control of a vacuum system in response to variations in temperature in a catalytic bed thereby to control a vacuum-operated bypass valve. The temperature responsive valve features a high temperature section that is essentially thermally isolated from a valve section thereof. Movement of a thermally responsive element in the high temperature section is transmitted to a novel valve arrangement in the valve section, thereby to control the vacuum operated r valve, which may be at a remote location.

Accordingly, one object of `the instant invention is an improved temperature responsive valve.

Another object is an improved snap-acting temperature responsive valve.

Another object of the instant invention is an improved temperature responsive valve that eiects thermal isolation of a high temperature section from a valve section.

Other objects and advantages of the disclosed exemplary embodiment of the instant invention will be apparent in the following specication, claim and drawings wherein:

FIGURE 1 is a side elevational View of a temperature responsive valve in accordance with one embodiment of the instant invention; Y

FIGURE 2 is a cross sectional view taken substantially along the line 2 2 of FIGURE l; and

FIGURE 3 is a fragmentary View similar to FIGURE l showing the snap-action blade and valve in the open condition.

As best seen in FIGURE 1 of the drawings, a snapacting temperature responsive valve 200, in accordance United StatesPatent O ice with an exemplary embodiment of the instant invention, comprises a thermally responsive section 202 and a valve section 204. The temperature responsive Valve 200, is adapted to be secured to the outer wall of, for example, a catalytic type mutlier, as by turning a threaded section 206 on a tting 208 into a complementary aperture in the muier (not shown).

The temperature responsive section 202 comprises a tubular member 210 having a positive coecient of expansion that lis secured to the tting 208 as by welding. The tubular member 210 is closed by an end plug 212 that is secured thereto as by welding. The end plug 24 has a truncated conical seat 214 for the acceptance and positioning of an outer end portion 216 of a rod 218. The rod 218 is made from material, for example, quartz, that is essentially thermally nonresponsive.

An inner end portion 220 of a rod extension 221 bears directly against a nondevelopable surface 222 of a snapacting blade 224. The snap-acting blade 224 is secured to a mounting bracket 225 as by a pair of rivets 226 and 227 (FIGURE 3). The mounting bracket 225 is of generally U-shaped construction, leg portions 230 and 232 thereof terminating in foot portions 234 and 236, respectively. The foot portions 234 and 236 of the mounting bracket 225 are secured topa base plate 238, as

A by a pair of rivets 240 and 242.

A blade control spring 250 is secured to the mounting bracket 225 -by the rivets 226 and 227 and has an end portion 252 that continuously engages the center of the nondevelopable surface 222 on the blade 224 against the end portion 220 of the rod 221 at all times.

A Calibrating screw 254 extends into a threaded bore 256 in the base plate 238, in outer end portion 258 thereof being accepted in a complementary slot 260 in the bracket 225.

A cover member 261 is secured to the base plate 238 i as by crimping an edge portion 262 over the base plate 238 and to this tting 208 as by Welding.

A free end portion 270 of the snap blade 22,4 is engageable with a ball type valve 272 that is adapted to be seated on a truncated conical valve seat 274 in a valve fitting 276. The ball valve 272 is normally biased to the open condition by a helical compression spring 278 that extends between a seat 280 in the valve tting 276 and the ball 2"/2 itself. Movement of the ball valve 272 under the bias of the spring 27S is controlled by the position of the end portion 270 of the blade 224 which is, in turn, controlled -by longitudinal expansion and contract-ion of the tube 210 due to a change in environmental temperature condition. Opening movement of the end portion 270 of the blade 224 is limited by an adjustment screw 286.

A flow path through the valve section 204 of the temperature responsive valve 200 is effected by a central passage 290 in the valve iitting 276, which communicates with the interior of the valve section 204 upon opening of the ball valve 272. An aperture 292 in the base plate 238 provides a flow path through the valve section 204.

From a study of the orientation of the above described structural elements, it should be apparent that relatively exact calibration of the valve section 204 can be accomplished by advancement or retraction of the Calibrating screw 254 and adjustment screw 286 which controls opening and closing movement of the blade 224 and thus the valve 272.

It is to be noted that a valve control member is normally biased into engagement with an element that is movable in direct relation to changes in the thermal environment. Since the valve control member is thus biased into constant and intimate engagement with the thermally responsive element, there is a minimum of lost motion and the valve control member.

In addition, the valve control member is mounted in a manner that facilitates calibration of'the thermally responsive valve by adjustment of a readily accessible calibration screw. Advancement-or retraction of the calibration screw results in varying the angular relationship between the fulcrum Vfor the valve control member, the point of engagement with the thermally responsive element, and the point of engagement with the fluid flow control valve. In this manner, relatively exact control of the opening movement of the fluid ow control Valve can *be effected.

Further, the flow control valve of the instant invention is normally biased into engagement with the control member so that lost motion between the valve control member and the vball Valve is minimized.

It is also to be noted that the valve and high temperature y sections of the improved thermally responsive valve herein disclosed, are separated, thereby to minimize the inherently deleterious effect of the catalytic bed of a smog-reducing muffler on operation of the valve. However, the

thermally responsive section is related to the valve sec-l tion in such a manner that relatively minute movements of the thermally responsive member are positively transmitted tothe valve section which react thereto.

It is to be understood that the specific construction of the improved temperature responsive valve herein disclosed andl described is presented for the purpose of explanation and illustration and is not intended to indicate limits of the invention, the scope of which is defined by the following claim.

What is claimed is: A temperature responsive valve comprising a valve section Y defining a fluid lilow path including a mounting base having a conical valve seat thereon, a ball type valve aligned with the valve seat on said base and movable into engagement and disengagement therewith to close and open said flow path, respectively, a valve spring constantly biasing said valve away from said seat and ybetween movement ofthe lthermally responsive member al snap-acting blade having one end portion adjustably supported by said base, said snap-acting blade hav" l ing a nondevelopable surface and a free end portion t for controlling movement of said valve, said valve spr-ing constantly biasing said valve against the free end portion of said blade, resilient means on said baseengageable With one side of the nondevelopable surface of said blade for continuously biasing said blade in one direction, a thermally responsive section substantially thermally isolated from said valve section comprising a thermally responsive member having one end portion y xedly supported with respect to said base and a free end portion, l a thermally nonresp onsive member having one end portion engaging and movable with the free end portion of said thermally responsive member, and another end portion extending into said valve section into engagement with the other side of the nondevelopable surface of said snap-acting blade, said valve being movable into and out of engagement with said valve seat upon movement of the free end portion of said-snapacting blade in response to movement of said thermally responsive and nonresponsive members.

References Cited in the le of this patent UNITED STATES PATENTS Branson et al. 'Oct. 3, 1961 

